A man employed to guard a building, a site, or a piece of property, especially at night. Think of a construction site after dark, or an old factory, with one person walking around with a torch and checking that the doors are locked.

employed to guard受雇看守 a building, a site, or a piece of property建築物、工地或一項財產 A man的人 especially at night尤其是在夜裡 Think of想像 a construction site after dark天黑後的工地 or an old factory或一間老工廠 with one person walking around with a torch有一個人拿著手電筒四處走動 and checking that the doors are locked並檢查門有沒有鎖好

The full phrase 'night watchman' is very common, and often the word simply means that. It is an older-sounding word.

The full phrase完整的說法 'night watchman'（夜間警衛） is very common很常見 and often the word simply means that而這個字通常就是指這個意思 It is這是 an older-sounding word一個聽起來比較老派的字

Modern job advertisements say 'security guard' or 'security officer', partly because 'watchman' contains 'man' and the job is not only for men — but there is no settled replacement ('watchwoman' exists but is rare, and 'watchperson' sounds odd), which is exactly why the whole word has quietly given way to 'security guard'.

Modern job advertisements現代的徵才廣告 say會說 'security guard' or 'security officer'「security guard（保全）」或「security officer（保全人員）」 partly because部分原因是 'watchman' contains 'man'「watchman」裡面有「man」 and the job is not only for men而這份工作不是只有男性能做 but there is no settled replacement但又沒有一個大家都接受的替代詞 ('watchwoman' exists but is rare（「watchwoman」是有這個字，但很少見 and 'watchperson' sounds odd)「watchperson」聽起來又很怪） which is exactly why這正是為什麼 the whole word has quietly given way to 'security guard'整個字已經悄悄地被「security guard」取代了

You still meet 'watchman' constantly in older books, in the Bible, in history, and in Taiwan and Hong Kong English where it is a normal everyday word for the person at the gate of a building or a school.

in older books, in the Bible, in history在比較舊的書裡、在聖經裡、在歷史裡 You still meet 'watchman' constantly你仍然會不斷遇到「watchman」這個字 and in Taiwan and Hong Kong English而在台灣和香港的英文裡 where it is a normal everyday word它是個很平常的日常用字 for the person at the gate of a building or a school指大樓或學校門口的那個人

There is also one special use to be ready for: in cricket, a 'nightwatchman' is a weaker batsman sent in late in the day to protect the better players, which has nothing to do with guarding a building.

There is also one special use to be ready for還有一個特別的用法要留意 in cricket在板球運動裡 a 'nightwatchman' is a weaker batsman「nightwatchman」是指較弱的打者 sent in late in the day在一天快結束時被派上場 to protect the better players用來保護較強的打者 which has nothing to do with guarding a building這跟看守建築物完全沒有關係